In a mesh BSS (MBSS), according to the 802.

a mesh portal is a device that connects a mesh BSS (MBSS) to an Ethernet network, such as the Internet. A mesh portal acts as a bridge between the wired and wireless domains, and allows the mesh stations to communicate with external networks. A mesh portal is also a mesh point, which means it can forward traffic within the MBSS.

The other options are not correct. Option A. Mesh Gate is a device that connects a mesh BSS (MBSS) to another mesh BSS or another wireless network, such as an infrastructure BSS or an ad hoc network2. A mesh gate acts as a gateway between different wireless domains, and allows the mesh stations to communicate with other wireless networks. A mesh gate is also a mesh point, which means it can forward traffic within the MBSS. Option B. Mesh Switch is not a valid term in the 802.11 standard. Option C. Mesh Router is also not a valid term in the 802.11 standard.